Method of and apparatus for cleaning gases



May 22, 1923.

A. N. DIEHL METHOD OF AND APPARATUS FOR CLEANING GASES Filed Aug. 5, 1919 4 Sheets-Sheet 1 fWITN ESSES Ww AM May 22, 1923. 1,45%34 A. N. DIEHL METHOD OF AND APPARATUS FOR CLEANING GASES Filed Aug. 5, 1919 4 SheetsShe et 2 May 22, 1923.

A. N. fiDIEHL METHOD OF AND APPARATUS FOR CLEANING GASES FiledAug. 5

, 1919 4 Sheets-Sheet 3 INVENTOR WITNESSES -May 22, 1923.

A. N. DIEHL METHOD OF AND APPARATUS FOR CLEANING GASES Filed Aug. 5 1919 V4 Sheets-Sheet 4 INVENTOR WITNESSES Patented May 22, 1923.

METHOD OF AND APPARATUS FOR CLEANING GASES.

Application filed August 5, 1919.

To all wil ow-i2. m (11/ comm-11 Be it known that I, Amunosn N. DinHr, a citizen of the l nited States. and resident of Duquesne, in the county of Allegheny and State of Pennsylvania. have invented certain new and useful Improvements in Methods of and Apparatus for Cleaning Gases. of which the following is a specification.

My invention relates to cleaning air and other gases, and the removal of liquids or of dust and other finely divided solids contained in such gases. and while not limited to such use, more particularly relates to clean ing the combustible gases evolved in a blast furnace and used in heating hot blast stoves, for firing steam boilers. and in the operation of gas engines using blast furnace gas as fuel. and for similar industrial purposes.

One object of my invention is to provide a novel method of cleaning gases whereby finely divided solids or liquids in suspension in the gases are easily and quickly removed in a cheap and economical manner.

Another object of my invention is to provide a. novel method of cleaning gases by the use of which finely divided solids or liquids in a flowing column of gases are separated therefrom and collected, and by which the collected impurities are removed and isolated and deposited out of the path of the column of gases.

Another object of my invention is to provide an improved method of cleaning gases in the use of which the movement of finely divided solids or liquids carried in suspension in a flowing column of gases is arrested and retarded, and the arrested impurities are separated and removed from the traveling column of gases. 1

A further object of my invention is to provide an improved method of cleaning gases by which counter-currents are created within a traveling column of gases and are utilized in separating and removing finely divided solids or liquids from the flowing column of gases.

A still further object of my invention is to provide apparatus for cleaning gases of improved construction and having novel means whereby the movement of impurities such as dust or finely divided solids and liquids in suspension in a flowing column of gases is arrested or retarded and the re tarded impurities are separated and removed Serial No. 315,519.

from the column of gases without interruption in the flow of the column of gases.

A further object of my invention is to provide apparatus for cleaning gases having improved means whereby the direction of movement of finely divided solids or liquids in a moving column of gases is changed and controlled in removing the dust or solids from the gases.

A further object of my invention is to provide gas cleaning apparatus of improved construction having novel means whereby counter-currents formed within a moving body of gases and the cmmter-currents are utilized in removing dust or finely divided solids or liquids in suspension in the gases and whereby the dust or other solids areseparated from the column of gases.

Still further objects of my invention cons st in providing apparatus having the novel constructions. combinations, and arrange ment otparts shown in the drawings, to be more fully described hereinafter and to be particularly pointed out in the appended apparatus claims.

Referring now to the accompanying drawings. forming part of this specification, Figure 1 is a plan showing one arrangement of gas cleaning apparatus constructed and arranged in accordance with my invention and adapted for use in carrying out the method forming part of my invention.

Figurc 2 is a side elevation of the ap-- paratus shown in Figure 1..

Figure 3 is a transverse sectional elevational elevation taken on the line ill- H1 of Figure 2.

Figure at is a sectional elevation, partly in section. showing one fond of separating mechanism. as constructed and arranged. and as applied for use in carrying out the method forming part'of this invention.

Figure is an enlarged sectional detail showingthe construction of a preferred form of the screen or filter forming part of my improved apparatus.

Figure 5 is a sectional plan on an enlarged scale. of the separating apparatus shown in Figure 4. the section being taken on the line V V of Figure 4.

The drawings show my improved apparatus applied to the gas main of a blast furnace for use in cleaning the gases evolved in the blast furnace, during the passage of the gases from the furnace to the hot blast stoves. It will be obvious however, that the apparatus also is applicable to steam boilers or other apparatus of utilization.

In the accompanying drawings, the numeral 2 designates a gas cleaning chamber having a gas inlet 3 (Figures 4 and 5) on its lower end. The inlet 3 connects with the outlet 4 on the upper side of the gas box 5 which extends lengthwise horizontally below the cleaning chamber 2. The gas box 5 has a supply conduit or flue 6 connected thereto through which rough cleaned or, in some cases, raw or uncleaned gases are conducted into the gas cleaning chamber 2, a valve 7 on the conduit 6 providing means for shutting off the supply of gases to the gas box 5. The upper end of the cleaning chamber 2 has a gas outlet 8 therein which is connected by the gas flue to a horizontally extending! main clean gas flue or gas main 10.

Mounted within the chamber 2 so as to turn on a vertical axis, is a rotatable dust collector which, as shown, in Figures 4 and 5, comprises oppositely extending hollow arms12, 12, having inwardly converging top and bottom sides 13 and 14 and open outer ends, a boss 15 connecting the adjacent top sides and a similar boss 16, the bottom sides. (See Figures 4 and 5.) The bosses 15 and 16 have screw threaded openings therein in which the threaded ends of pipes 17 and 18 are secured to form a sectional hollow shaft for the hollow arms of the rotating collector.

Positioned within the cleaning chamber 2 is a stationary cylindrical screen 19 which, as shown, is formed of case metal, its surface being perforated by a multiplicity of small apertures or holes. The screen 19 is secured by the inturned flanges 21 to the bottom of the cleaning chamber 2 and its upper edge is provided with an outwardly turned flange 22 to which a detachable lid or cover 23 is secured. this cover having a stufling box 24 and gland 25 thereon, through which the section 17 of the hollow shaft extends. The lower section 18 of the hollow shaft projects downwardly through the stufling box 26 and gland 27 on the lower side of the gas box 5 located below the cleaning chamber 2 and is mounted by its lower end in a step bearing 28 positioned beneath the gas box 5.

The open ends of the arms 12 have recessed flanges 12 and in the recesses is a compressible packing material 12 which is in contact with the inner surface of the screen 19.

The foraminous partition or screen 19 is covered on its outer surface preferably with a filtering medium" such as a plurality of layers of loosely woven fabric or fibrous material 29. The-material 29 may be metal- .lie or non-metallic, steel wool, copper wool,

flocculent or woven asbestos, and similar materials being particularly adapted for 'use in cases wherein the gases are highly heated, as, for example, blast furnace coke oven and producer gases. (See Figure 4 Wire netting or similar woven wire fabric may be employed as an envelope for the pads of steel or mineral wool and similar materials, wlhen such materials are used in forming the fi ter.

A series of wraps, loosely wound, of metal wire also may be substituted for the filtering medium shown'in Figure 4 and a series of wraps of woven wire fabric also may be used instead of the fibrous material 29 shown in Figure 4 The upper section 17 of the hollow shaft extends upwardly through a stufling box 30 and gland 31 provided on the elbow 32 forming part of the gas outlet 8 leading from the cleaning chamber and projects into the stuffing box '33 and gland 34 on the end of the stationary gas flue 35 which is located to the one side of the cleaning chamber 2. A worm gear 36, which is keyed or otherwise fastened on the hollow shaft, meshes with the worm 37 on the worm shaft 38 and the worm shaft is coupled to the armature shaft 39 of the driving motor 40, the motor being mounted on the platform 41 positioned above the gas cleaning chamber 2. The gas flue 35 connected to the upper end of the low rotating shaft, to a 0rd means for stopping the fiow of gases through the hollow shaft into the dust catcher 42. The dust catcher is also provided with an outlet flue or pipe 44 adjacent to its upper end, the pipe 44 having a valve 45 thereon to stop the flow of gases therethrough from the dust catcher and this outlet pipe 44 is connected at one end to the inlet on the exhaust blower or fan 46, the shaft 47 of the fan being connected to the armature shaft 48 of the fan driving motor 49, and the fan and motor being mounted upon a suitable base 50 provided for that purpose.

In Figure 1 of the drawings two gas cleaning units are shown, one for each of the two stoves 61, each unit having a cleaning chamber 2 and dust catcher 42 with the dust catchers connected by gas flues 44 to the sin.

partition 52. The upper end of the partition is secured to an annular plate 53 which is fastened on its outer marginal edge to the shell of the dust catcher 42. The bottom 54 of the dust catcher is'conical and has an outlet opening 55, throughwhich the finely divided solids or liquids separated from the body of gases and collected in the bottom of the dust catcher, are removed from time to time. The valve 56 on the outlet provides means for closing the outlet opening, except when removing the collected materials from the bottom of the dust catcher.

' An overhead gas main 57 leads from the blast furnace or a plurality of furnaces, and branch pipes 6 leading from the top of the gas main 57 connect the rough gas main 57 with each inlet on each gas box 5, these gas boxes leading to the inlets on the cleaning chamber 2. The branch gas flue 10 from the gas outlet of the cleaning chamber 2 connects witha vertically extending pipe 58 which opens at its lower end into the gas box 59 of the gas burners-60 on the hot blast stoves 61 and its upper end' 62 opens into a clean gas main 63 which extends horizontally parallel with the rough gas main 57, the gas main 63 delivering the cleaned gases to the gas engines, steam boilers, or other place of use.

The outlet 64 on the exhaust fan or blower 46 is connected to a branch gas main 65 which, as shown, connects into the rough gas main 57 and has a branch 66 which leads to a place of use for the gases withdrawn through the cleaning chambers in removing the dust from the gases passing through the cleaning chamber.

In carrying out my improved method of cleaning gases with apparatus constructed and applied for use, as shown, the rough or uncleaned gases are caused to pass from a blast furnace through the rough gas main :37. The uncleaned gases flow from the rough gas main 57 through the branch pipes 6 into the gas box 5 located below the gas cleaning chamber 2' and, rising upwardly within the chamber 2 pass through the screen 19 and fibrous filter or dust retarding medium 29. The filtered gases then rise upwardly and pass through the outlet 8 of the cleaning chamber into and through the branch pipe 10 into the clean gas main (See Figures 1 and 2.) The cleaned gases are then delivered by the gas main 58 to the box 59 for the gas burners on the hot blast stoves and any other desired place of use.

The gases pass through the screen 19 under a pressure of several ounces and the surface of the screenis made sutticiently large to not obstruct or retard the flow of gases through to a great or harmful extent.

The motor 40 is started to rotate when iize apparatus is put into use so as to turn conduit leading from the cleaning chamber '2, to the inlet of the exhaust fan 46.

The gases will readily pass through the foraminous screen 19 and filtering medium or covering therefor but the travel of any finely divided solids or fluids in the gases,

while not necessarily stopped, will be hindered or retarded in passing, and will collect upon the surfaces of the filtering medium. The ends of the rotating collector arms will traverse the inner surface of the screen and, as the slot inthe outer end of each arm 12 sweeps past a given point on the screen 19, a counter-current is created in the column of gases and any finely divided deposits-on the screen and filtering medium at such point will be removed by the collector arms and will be carried into the hollow collector arms 12.

Owing to the partial vacuum created and maintained within the hollow arms 12 of the collector, the velocity of the reversely flowing portions of the gases entering the hollow arms is very greatly increased and in withdrawing the gases through the screen 19, ,into the hollow collector arms 12 and hollow shafts 17, retarded and arrested particles of finely divided solids or liquids on the screen and screen covering 29 are taken up and withdrawn from the screen and are carried through the hollow shaft into the lower part of the dustcatcher 42. The gases withdrawn through the hollow arms are heavily laden with the concentrated dust, and finely divided solids or liquids removed from the screen surface, and in traversing the spiral path within the dust catcher 42 the major portion of the impurities will become deposited in the lmf tom of the dust catcher. The gases withdrawn in this way from the cleaning chamber 2 into the dust catcher 42 rise upwardly and pass through the outlet on the dust catcher into and through the flue 44 and the exhaust fan 46. As the discharge side of this exhaust fan delivers the gases under pressure. gases passing from the fan will be forced through the conduit 64 and returned to. the rough gas main 57 or other -main, in which the pressure is at or somewhat below that of the gases from the fan 46.

It has been found by experiment that under normal conditions in treating blast furnace gases by my improved method, the quantity of gases withdrawn through the collector arms is very small relative to the large volume of gases passed through the screen,

and on account of the increased velocity of the withdrawn gases, the impurities collected on any given portion of the screen or filter are removed in much less time than .is required for them to become deposited the solids is necessary the gases will be again passed through another gas cleaning unit or series of units constructed in the manner which has been described, or such gases may be passed through a .wet gas washer, or other form of washer as desired.

The operations which have been described are carried out continuously, so long as the gas supply is maintained, or until it is desired to stopthe operation of the apparatus.

Where there is a very large supply of gas to be cleaned which is to be used in a large number of different localities, the gas cleaning units, preferably, will be made relatively small and a series of such units will be em-.

ployed and independently operated, one fan, preferably. being employed with the plurality of cleaning chambers.

By the term finely divided materials as used in the claims and elsewhere herein, is meant finely divided-solids and liquids and any other impurities carried in suspension in the gases and capable of being removed with my improved apparatus.

The advantages of my invention will be apparent to those skilled in the art. By employing my improved method the dust, liquids, or other finely divided materials contained in the gases are rapidly and efficiently removed and the cleaned gases will contain but a small percentage of dirt or other foreign material per cubic foot of gases; The apparatus is simple and is easily kept in repair.

Modifications in the construction and arrangement of the apparatus may be made without departing from my invention.

The screen 19 may be divided into sections which are movable and have either a rotary, oscillating or reciprocating movement. In such case the cleaning operation will not be continuous but will be intermittent. The apparatus shown is only one form of apparatus adapted for use in cleaning gases by my improved method. "When an intermittently operated apparatus is employed the screen ma be cleaned by air, gas, steam or water. y invention is adapted for use in effecting the removal of acid or other liquids from producer or coke-oven gases and rating various changes in the apparatus may be made within the scope of the invention as said gases in said separator, and returning said reversed or withdrawn gases to the uncleaned column of gases to be again passed through said screen.

2. Apparatus for cleaning gases comprising a gas main and a stationary circular screen in said main through which the gases are caused to pass, said screen having means for interrupting without stopping the passage of finely divided solids in the gases, means covering successively different portions of the inner surface of the screen and arranged to revolve so as to traverse the entire inner surface of said screen at each revolution, means for creating a suction within the screen covering means to withdraw gases from the main and remove finely divided materials in passing through the portions of the screen opposite the screen covering, means for separating the with drawn gases from the solids contained therein. and means for returning the withdrawn gases .after the-solids have been separated therefrom to the gas main to again pass through said screen.

3. Apparatus for cleaning gases comprising a gas main, a stationary circular screen in said main through which the gases are caused to pass, said screen having means for interrupting without stopping the passage of finely divided materials in the gases, means covering a. portion of the inner surface of the screen and movable relatively thereto, arranged to traverse the entire screen surface, means for creating suction within the screen covering, means to withdraw gases from the main and remove finely divided materials in passing through the portions of the screen opposite the screen-covering, means for sepathe withdrawn gases from the finely divided materials contained therein, and means for returning the withdrawn gases to the gas main to be again cleaned.

4:. Apparatus for cleaning gases compris ing a gas main, a circular stationary screen in said main through which the gases are caused to pass said screen having a permeable covering on its outer surface for interrupting the passage of finely divided materialsin the gases, a pair of diametrically opposite rotary hollow arms mounted within said screen, said arms having elongated slotted ends in rubbing contact with the inner surface of said screen, means for I rotating said arms, means for creating suction within said arms to withdraw gases from the main and remove finely divided materials in passing through the portions of the screen opposite the slotted ends of said arms, means for separating the withdrawn gases from the finely divided materials contained therein, and means for returning the withdrawn gases to the gas main.

5. In an apparatus for cleaning gases the combination with a gas main and a foraminous circular partition having a permeable covering, of a pair of diametrically opposite rotary hollow arms mounted within said partition,'said arms having elongated slotted ends in rubbing contact with the inner surface of said partition, means for rotating said arms, means for creating a suction within said arms to withdraw gases from the main and remove finely divided materials in passing through the portions of the screen opposite the slotted ends of said arms, means for imparting a whirling motion to said withdrawn gases to separate the finely divided materials contained therein from the gases, and means for returning said withdrawn gases to the gas main.

6. The method of cleaning gases which consists in passing a column of gases through ascreen to retard and arrest the passage of finely divided materials therethrough, reversing the direction of flow of portions of the gases through successively different parts of saidscreen and with suf therethrough, causing a reverse flow of portions of the cleaned gases through successively diflerent parts of said screen, and increasing the velocity of said reversed'fiow of cleaned gases sufficiently to remove the retarded and arrested materials from the screen, passing the withdrawn or reversed flow of gases through a separator to remove the arrested materials therefrom, and returning said reversed or withdrawn gases to the uncleaned column of gases to be again passed through said screen.

In testimony whereof, I have hereunto set my hand.

AMBROSE DIEHL. 

